Hammer mill and blower arrangement



www NLM" July 28, 1953 B. T. sANDoR 2,645,934

HAMMER MILL AND BLOWER RRANGEMENT Filed Dec. 14. 1951 INVENTOR.

BY I. fx/Q Patented July 28, 1.9.53

HAMMER MILL AND BLOWER ARRANGEMENT Bela T. Sandor, Ayr, Scotland Application December 14, 1951, Serial N o. 261,614 In Great Britain November 27, 1950 6 Claims.

The present invention relates to hammer mills, and more particularly to an arrangement combining a hammer mill and a blower.

It is known to combine hammer mills and similar disintegrators with a rotary blower mounted on the shaft of the hammer mill rotor. This arrangement requires an air conduit between the disintegrator casing and the blower casing which is disposed perpendicular to the planes in which the disintegrating members and the fan blades rotate. Consequently, the air current produced by the blower removes disintegrated material from the hammer mill in a direction which is normal to the direction in which the disintegrated material is blown by the air current produced by the hammer mill rotor, and the two air currents do not cooperate.

The unused air current of the hammer mill rotor throws and presses disintegrated material to the casing of the hammer mill where it piles up. It has been proposed to arrange an air inlet on the bottom of the hammer mill casing for removing disintegrated material accumulated thereon.

This method, however, has not been proven to be effective, and the disintegrated material accumulating on the bottom of the hammer mill casing causes clogging of the hammer mill in the known constructions.

In arrangements of this type a great portion of the power of the blower is consumed for clearing the bottom of the hammer mill casing, and consequently the size of the blower motor is far greater than required for only transporting disintegrated material.

It is an object of the present invention to overcome these disadvantages and to provide an arrangement by which disintegrated material is guided out of the hammer mill in such a manner that it meets with almost no resistance.

It is also an object of the present invention to provide a hammer mill arrangement wherein the disintegrated material is fast and reliably removed by the combined action of a hammer mill rotor and a blower.

t is a further object of the present invention to provide a hammer mill arrangement wherein on account of the lowered resistance against removal of the disintegrated material, the size and power consumption of the motor driving the blower may be reduced.

It is a still further object of the present invention to reduce the size of the motor driving the blower in order to permit the use of a mobile unit comprising a detachable blower and a motor driving the same.

1t is also an object of the present invention to arrange the discharge end portion of the duct through which disintegrated material is removed from the hammer mill in a tangential direction of the hammer mill rotor.

With these objects in View the present invention mainly consists in the arrangement of a hammer mill rotor on a substantially horizontal shaft. Around the rotor of the hammer mill a perforated substantially cylindrical screen member permitting passage of disintegrated material is arranged. The screen member is surrounded by an outer casing having a curved wall of evolute-like shape and constituting with the screen member a duct having a widened discharge end portion extending substantially tangentially to the rotor of the hammer mill so that disintegrated material may pass out of the duct with a minimum of resistance.

The discharge opening of the duct may be arranged adjacent to the bottom of the outer casing formed by the end portion of the curved wall.

Material disintegrated by the hammer mill is forced by the air current created by the rotating hammer mill rotor through the screen member and out of the duct. A blower connected to the discharge opening of the duct sucks disintegrated material in the same direction as it is blown by the hammer mill rotor, whereupon the disintegrated material is blown by the blower into a forked trunking system of discharge pipes. The discharge pipe of the blower may be used for transporting untreated material by means of the air current produced by the blower.

In contrast to the known constructions, the hammer mill is not rotated during such operations, resulting in an economical power consumption.

T he rotor of the hammer mill may be provided with additional fan blades in order to increase the eiciency of the blowing action of the hammer mill rotor.

The reducing of the resistance in the path of the disintegrated material, and the utilization of the air current created by the hammer mill rotor makes it possible to employ comparatively small blowers. Consequently the blower may be driven by a separate electric, gasoline, or diesel motor, and combined with the same to form a mobile detachable unit mounted on a carriage.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be 3 best understood from the following description of specic embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is a partly sectional side view of a preferred embodiment of the present invention; and

Fig. 2 is a partly sectional front view of the embodiment shown in Fig. 1.

Referring now to the drawings, the apparatus according to the present invention comprises a hammer mill rotor 2 mounted on a horizontal shaft I and surrounded by a substantially cylindrical screen member 3. Fan vanes 2 may b arranged on the rotor. Around the scr'een member an outer casing 4 is arranged which includes Ha curved wall extending spaced from the Iscreen member and constituting with the saine a duct for disintegrated material. The discharge fen'd portion of the duct is widened since the bottom portion II of the outer casing extends in a substantially tangential direction with respect to the cylindrical screen member and the hammer mill rotor. In the straight front wall 5 of the outer casing a discharge opening 8 is provided leading to an outlet conduit 9. Material to be treated is guided through the chute I in `the direction of the arrow through an opening E into the space within the screen member 3. During rotation of the hammer mill rotor the material entering through opening E is disintegrated and blown by the air current c reatedby the hammer mill rotor through the screen member and along the wall 4, I I out of the discharge opening Sinto the conduit 9.

with a removable cover 2k3.l

The discharge Conduit of the blower lo is pro;

vided with a two-way valve I5 having a piv'otd closure member I8 which is operated by a handle I9 and closes in the illustrated position the outlet conduit I6 which is used for conveying disintegrated material to a suitable container. In the position of the closure member I8 shown in Figure 2 an air current produced by the blower may be used for conveying any kind of material fed into hopper 2B and aperture 2l into conduit I'I which is provided with a Venturi-like rcon-` struction. 'Ihe abovel-described arrangementof the discharge conduit of the blower may be used independently from the hammer mill for conveying untreated material to a storage co'ntainer. y

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of hammer mill and blower arrangements differing from the types described above.y I e While the invention has been illustrated and described as embodied in an arrangemnet wherein the air current produced by the hammer mill rotor cooperates with the air -current produced by a blower to convey disintegrated material, it is not intendedto be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Foreign bodies, like stones or` metal pieces are thrown into pocket 22 provided Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the genericI or specific4 aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the mean- 'ing and range of equivalence of the following claims.v

i What is claimed as new and desired to be secured by Letters Patent is:

. 1. In `a hammer mill arrangement in combinatiorn a rotatable hammer mill rotor creating an outwardly directed air current; a perforated part cylindrical screen member extending partly around said rotor so as to form an open inlet passage While simultaneously permitting passage` of disintegrated material through the screen perforations; ia casing enclosing said screen member "andI including an at least partly curved duct wallhaving anend portion located adjacent to said screen member and extending from said end portion so that its other end portion is located spaced` from said screen member so as to form between itself and said screen member a diverging duct; blower means; and a straight converging duct means arranged in direction of and aligned with said diverging duct in said casing and securedwith its wider inlet and to said casing communicating with diverging duct and at its narroweroutlet end to said blower means, so that the combined air current produced by said hammer millrotor and said blower means forces the disintegrated material through said screen member intoas'aid divergentduct and from there to theconveijgent ductmeans, into said blower means tvitlfioutchang'ir'ig the direction of flow of said disintegrated material. l v l Y 2. In ,a hammer mill arrangement in combina-` tion a rotatable hammer mill rotor creating an outwardly directed air current, said hammer mill rotor including a rotor shaft and at least one fan vane' secured to said rotor shaft and projecting from the vsame in radial direction so as to increase theair current created by said hammermill rotor during rotation; a perforated part cylindrical screen member extending partly around said rotorso as to vforn'iV an open inlet passage while simultaneouslypermitting passage of disintegratin'g material through the screen perforations; a casing enclosing said screen member and including an at least partly 4curved duct wall having an end portion locatedadjacent to said screen member ander/tending from said end portion so that its other end portion is located spaced from said screen member so as to form between itself and said screen member a `diverging duct; blower means; and a vstraight converging duct means arranged in direction of and aligned with said diverging duct said casing and secured with its wider inlet'end to' said casing communicating with diverging duct and at its narrower outlet end to saidy blower means, so that thecombined air current produ'ced bysaid hammer mill rotor and said blower means forces the disintegrated materialthroughjsaidscreen member into said divergent duct' and from there to the convergent duct means into said blower means without changing Ithe direction of iiow of said disintegrated material. A n Y 3 In a hammer mill arrangement in combination, a rotatable hammer mill rotor creating an outwardly directed air current; a perforated part cylindrical screen member extending partly around said rotor so as to form an open inlet passage while simultaneously permitting passage of disintegrated material through the screen perforations; a casing enclosing said screen member and including an at least partly curved duct wall having an end portion located adjacent to said screen member and extending from said end portion so that its other end portion is located spaced from said screen member so as to form between itself and said screen member a diverging duct; rotary blower means having a shaft having an axis of rotation extending normal to the of said hammer mill rotor; and a straight converging duct means arranged in direction of and aligned with said diverging duct in said casing and secured with its wider inlet end to said casing communicating with diverging duct and at its narrower outlet end to said blower means, so that the combined air current produced by said hammer mill rotor and said blower means forces the disintegrated material through said screen member into said divergent duct and from there to the convergent duct means into said blower means without changing the direction of iiow of said disintegrated material.

4. In a hammer mill arrangement in combination, a rotatable hammer mill rotor creating an outwardly directed air current; a perforated part cylindrical screen member extending partly around said rotor so as to form an open inlet passage while simultaneously permitting passage of disintegrated material through the screen perforations; a casing enclosing said screen member and including an at least partly curved duct wall having an end portion located adjacent to said screen member and extending from said end portion so that its other end portion is located spaced from said Screen member so as to form between itself and said screen member a diverging duct; rotary blower means having a shaft having an axis of rotation extending normal to the axis of said hammer mill rotor; a straight converging duct means arranged in direction of and aligned with said diverging duct in said casing and secured with its wider inlet end to said casing communicating with diverging duct and at its narrower outlet end to said blower means, so that the combined ai-r current produced by said hammer mill rotor and said blower means forces the disintegrated material through said screen member into said divergent duct and from there to the convergent duct means into said blower means without changing the direction of ilow of said disintegrated material; and motor means mounted on said shaft of said blower means for driving the same, said motor means and said blower means constituting a detachable unit.

5. In a hammer mill arrangement in combination, a hammer mill rotor creating an outwardly directed air current; a perforated substantially cylindrical screen member having an air inlet and extending around part of said rotor and permitting passage of material disintegrated in the hammer mill through its perforations; an outer casing including a duct wall having a curved wall portion attached at one end thereof to said screen member and extending around a portion of the same spaced therefrom, and a bottom wall portion extending from the other end of said curved wall portion in a direction widely diverging from said screen member so that said screen member and said duct wall form an outwardly diverging duct having a wide outlet opening located oppositely a portion of said screen member; and a rotary blower means having a straight converging inlet conduit means including a bottom wall portion forming an extension of said bottom wall portion of said casing, said straight converging inlet conduit means being aligned with and extending in the same direction as said diverging duct and communicating at the wider end thereof with the same through said outlet opening which constitutes the inlet opening of asid inlet conduit means so that the combined air current produced by said hammer mill rotor and said blower means forces material through said screen member partly into said diverging duct and from there into said converging duct means, and partly directly through said outlet opening into said converging duct means.

6. In a hammer mill arrangement in combination, a hammer mill rotor having a horizontal axis and including a shaft and fan vane means secured to said shaft and creating an outwardly directed air current; a perforated substantially cylindrical screen member having an air inlet and extending around part of said rotor and permitting passage of material disintegrated in the hammer mill through its perforations; an outer casing including a duct wall having a curved wall portion attached at one end thereof to said screen member and extending around a portion of the same spaced therefrom, and a downwardly inclined bottom wall portion extending from the other end of said curved wall portion in a direction widely diverging from said screen member so that said screen member and said duct wall form an outwardly and downwardly diverging duct, said outer casing including a substantially vertical wall means extending transversely to said duct and being formed with a wide outlet opening located oppositely a portion of said screen member; and a rotary blower means having an axis of rotation extending horizontal and normal to the axis of said hammer mill rotor and including a straight converging inlet conduit means including a bottom wall portion forming an extension of said bottom wall portion of said casing, said straight converging inlet conduit means being aligned with and extending in the same direction as said diverging duct and communicating at the wider end thereof with the same through said outlet opening which constitutes the inlet opening of said inlet conduit means so that the combined air current produced by said hammer mill rotor and said blower means forces material through said screen member partly into said diverging duct and from there into said converging duct means, and partly directly through said outlet opening into said converging duct means.

B. T. SANDOR.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,446,221 Starr Feb. 20, 1923 1,713,957 Duvall May 21, 1929 2,068,383 Lindgren et al Jan. 19, 1937 2,184,123 Mankoif Dec. 19, 1939 2,403,638 Clark July 9, 1946 2,439,014 Luhrmann Apr. 6, 1948 2,494,705 Hamilton Jan. 17, 1950 2,505,023 Williamson Apr. 25, 1950 2,557,344 Erickson June 19, 1951 

